Apparatus for securing gasket prior to lid installation

ABSTRACT

A lid for a container forming an upper rim portion. The lid comprises a central portion and a peripheral skirt portion forming a downwardly disposed channel extending around the periphery of the lid. The channel is adapted to overlie the container upper rim portion and to hold a sealing gasket therein at an upper portion of the channel. The skirt portion forms a plurality of bendable flaps extending within said channel, each of which being movable from a first position wherein each said flap extends across a portion of said channel preventing said gasket from falling out of the channel to a second position wherein each said flap is positioned within a relief pocket formed within said skirt wall. Each flap is urged from said first position to said second position by the rim of the container as it is inserted within said channel and pressed into engagement with said gasket. The flap may be inserted in a clearance fit within said pocket and remains in said pocket once urged therein by said rim portion. Alternately each flap may be pressed into friction fit engagement within said pocket and is fixed within said pocket once pressed therein.

FIELD OF THE INVENTION

This invention relates to plastic containers, and in particular, to lids for such containers and a system for securing a sealing gasket within the lid prior to installation on a container.

BACKGROUND OF THE INVENTION

For certain uses of plastic containers, it is known and desirable to use an additional sealing means (such as a gasket or o-ring or the like) between the container upper rim and the downward groove formed around the periphery of the lid which is adapted to overlay the rim. In order to avoid gasket damage caused by inadvertent removal from the lid, it is desirable that gaskets be held firmly in lids during transportation and handling of lids regardless of lid stacking orientation. Known lids using additional seals such as gaskets or the like do not provide means to effectively secure the gasket within the downward peripheral groove of the lid in an economical and efficient manner nor do they secure the gasket in a way which causes no further significant interference or additional tensions between lid and container once they are assembled together.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a means to secure a gasket within an lid prior to installation of said lid on a container in an efficient and improved manner.

In accordance with an aspect of the invention there is provided a lid for a container, said container forming an upper rim portion, the lid comprising: a central portion and a peripheral skirt portion forming a downwardly disposed channel extending around the periphery of said lid, said channel adapted to overlie the container upper rim portion and to hold a sealing gasket therein, said skirt portion forming a plurality of bendable flaps extending within said channel, each of which is movable from a first position wherein each said flap extends across a portion of said channel preventing said gasket from falling out of the channel to a second position wherein each said flap is positioned within a relief pocket formed within said skirt wall.

In accordance with a further aspect of the invention, each said flap is urged from said first position to said second position by said upper rim portion as said upper rim portion is inserted within said channel as the channel overlies the upper rim portion, the gasket being positioned above said flap and pocket.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a bottom plan view of an embodiment of a lid in accordance with the invention;

FIG. 2 is a vertical section view of a peripheral portion of an embodiment of a lid and container in accordance with the invention prior to insertion of the container upper rim portion into the downwardly disposed channel of the lid;

FIG. 3 is a vertical section view of the peripheral portion of the lid and container corresponding to FIG. 2, with the upper rim portion coming into contact with flaps;

FIG. 4 is a vertical section view corresponding to FIGS. 2 and 3, showing the upper rim portion urging the flap toward a relief pocket while simultaneously flexing the locking flange segment outwardly;

FIG. 5 is a vertical section view corresponding to FIGS. 2, 3 and 4 showing the upper rim portion further urging the flap toward a relief pocket while flexing the locking flange segment outwardly;

FIG. 6 is a vertical section view corresponding to FIGS. 2 to 5 showing the upper rim portion engaging a gasket within the peripheral channel of the lid and the flap pressed into the relief pocket in friction fit;

FIG. 6 a is a vertical section view of an alternate embodiment of a lid and container, wherein flaps are positioned within pockets in a clearance fit;

FIG. 7 is a further vertical section of the embodiment of the lid of FIGS. 2 to 6 showing tear off strip removed;

FIG. 7 a is a further vertical section of the embodiment of the lid of FIG. 6 a showing the tear off strip removed;

FIG. 8 is a section view of a portion of the lid as formed by injection molding between a cavity side and core side of a molding apparatus, further illustrating the geometry of the core ring utilized to eject the lid from the core; and

FIG. 9 is a side elevation view of a portion of the lid and container.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In an example embodiment a plastic container lid (10) is disclosed for a container (12), the container having an upper peripheral rim portion (15) and upper and lower locking flanges (18, 20) around its upper peripheral rim portion for locking engagement with the lid. The lid has a central portion (14) and a peripheral skirt portion (16) which forms downwardly disposed peripheral channel (19) which is adapted to overlie the container upper rim portion (15) and to hold a sealing gasket (21) therein at an upper portion of said channel at a position above said upper rim portion. The skirt portion forms a plurality of bendable flaps (22) extending within said channel, each of which being movable from a first position (best shown in FIGS. 2 and 3) wherein each said flap extends across a portion of said channel preventing the gasket from falling out of the channel to a second position (best shown in FIGS. 5, 6 and 7) wherein each said flap (22) is positioned within a relief pocket (25) formed within the skirt portion wall.

As can be best seen in FIGS. 3, 4 and 5, each said flap is urged from the first position to the second position by the container rim portion (15) as the rim portion is inserted within said channel (19) and pressed into engagement with said gasket (21). In the embodiment shown in the Figures each flap (22) is formed on a wall (17) of the skirt portion (16) defining the skirt peripheral channel, at a position below each pocket (25). Each flap (22) may be bent from said first position into said pocket urged by the rim portion (15) as it is inserted within said channel (as shown in FIG. 6). When the lid is fully installed on the container (as shown in FIG. 6), the upper rim portion (15) of the container has presses the flaps (22) firmly in the relief pockets (25), with the container rim itself being held in the peripheral channel of the lid.

In an example embodiment, the flaps are approximately ½ inch wide and long and 0.03 inches thick, although it should be understood that the size and thickness of each flap may be varied and such variations are within the scope of this invention.

In the embodiment shown, the flap (22) in the first position extends across only a portion of the channel (19), and leaves an open portion of the channel. This open portion allows gasket (21) to pass through upon slight compression of the gasket away from wall (17) toward the side of the channel opposite wall (17).

Any gasket, such as an o-ring or the like may be used in accordance with the invention, provided that it is sized to fit within the container lid channel (19). In the embodiment shown in the drawings, the gasket is compressible and resilient returning to its original shape (as shown in FIGS. 7 and 7 a) after the upper rim portion (19) compresses same (as shown in FIG. 6). It should be understood that a less resilient gasket may be utilized which remains compressed after the upper rim portion is removed. In a typical example of the container and lid used in accordance with the invention, the size of container (12) is such that it holds typically from about 4 to 20 litres. The container (12) and lid (14) are most commonly made from plastic, such as high density polyethylenes (HDPE) or polypropylenes. However, any plastic or other material with similar characteristics could be used for lid (10). The resilience of the lid and flaps may be varied as desired by using varied compositions of materials such as plastic.

The shape and geometry of the relief pocket is influenced by the resilience of the material used. For lids made of less resilient materials, flaps (22 a) preferably have a clearance fit as shown in FIGS. 6 a, 7 a within the relief pockets (25 a), as the flaps will remain bent in relief pockets once urged therein by said rim portion (15).

For lids made of a resilient material, the relief pockets (25) must have some means of holding the flaps (22) in place once bent therein by the upper rim portion (15), as the resilience/elasticity of the flap will give them a tendency to snap back out. The embodiment shown in FIGS. 2 through 7 achieves the holding of flaps (22) within relief pockets (25) by way of a reversed taper at bottom of relief pocket and at end of flaps. This ensures that flaps will not interfere with or resist in any way to repeated openings of the lid. In the embodiment shown in FIGS. 2 to 7 the lid is formed of resilient plastic, with each said flap being resiliently biased in said first position. Each said flap once urged into the pocket is pressed into friction fit engagement within said pocket and is fixed within said pocket once pressed therein by said rim portion. The upper portion (27) of the pocket is downwardly tapered as it extends outwardly from the pocket. The upper portion (27) engages in friction fit an upper portion (29) of said flap (22) within said pocket, thereby securing said flap (22) within said pocket (25).

In the embodiment of the lid and container shown in the drawings, the skirt portion forms a peripheral groove (30) dividing the skirt into an upper portion (32) and a lower tear-off strip portion (34). The upper portion has intermittent locking flange segments (36) for engaging the upper locking flange, formed from the bottom of the upper rim portion. The tear-off strip portion has a second locking flange (38) for engaging the other of the container locking flanges. As can be seen in FIG. 9, openings (40) are formed in the skirt upper portion on either side of the intermittent locking flange segments (36) and bordering on the annular groove (30), so that the openings form weakening notches upon removal of the tear-off strip portion (34) to facilitate upward deflection of the lid annular skirt (16) in the area of the intermittent flange segments (36) to facilitate removal of the lid. As can be seen in FIGS. 4 and 5 as the upper rim portion (15) is inserted into the channel (19), it engages the locking flange segments (36), flexing them along with the outerwall (17) of the lid skirt upper portion (32) outwardly. Once the upper rim portion clears the locking flange segments, the outer wall flexes back (as seen in FIG. 6, 6 a), and the flaps are urged into the relief pockets.

In the preferred embodiment as shown in the drawings, a gasket (21), such as a compressible o-ring seal, is installed within the channel (19). In order to ensure that the gasket does not fall out of the channel, additional holding means such as flaps (22) or (22 a) are positioned between adjacent locking flange segments (36). In the embodiments shown in the Figures, openings (40), located on either side of the intermittent locking flange segments (36), allow flexing the portion of the intermittent locking flange segment to clear the container upper locking flange (18) and allow the lid to be removed. If more locking flange segments (36) were introduced than that of the embodiments shown in the Figures, the lid skirt would become more rigid and would make removal of the lid more difficult.

As can be seen in FIG. 9, it should be understood that openings (40) border on the annular groove (30), so that upon removal of tear-off strip portion (34), windows (40) turn into downwardly disposed V-shaped notches on either side of the locking flange segments (36). The part of skirt or upper portion (32) located between openings/windows (40) that contains locking flange segments (36) thus becomes a priable portion that can be pried outwardly and upwardly to release the locking flange segments (36) from container upper locking flange (18) and thus allow for the easy removal of lid (10) from container (12).

Variations in the nature of the opening (40) are described in U.S. Pat. No. 6,543,635 to Ciccone, said patent being incorporated herein by reference. For example opening (40), may be covered with a thin membrane which can tear as priable portions are pried upwardly, or, if windows (40) are made thicker, they can stretch elastically and act as springs to help return priable portions to the locking position. The membranes of windows (40) typically are about 0.2 to 0.5 mm (0.008 to 0.020 inches) thick, and prevent dirt or other foreign matter from entering windows (40) and collecting on flange (20). If desired, membrane windows (40) can have strengthening or reinforcing ribs especially if it is desired that the membranes not tear upon the lifting of priable portions. With ribs, priable portions will more readily resume their original shape after being lifted.

A variation in the opening includes a membrane having an opening therethrough bordering on the annular groove (30). The removal of tear-off strip portion (34) thus leaves downwardly disposed open, inverted V-shaped open notches on either side of the locking flange segments (36) to make the lifting of priable portions easier. The openings or notches can be any shape or configuration desired, even narrow vertical slits, if it is desired to prevent dirt or debris from passing through openings (40).

Preferably flaps (22) may be positioned around the periphery of the lid at regularly spaced intervals. Preferably flaps (22) are positioned between locking flange segments. In the embodiment shown in the drawings, two flaps (22) are positioned between adjacent locking flange segments (36). As best seen in FIG. 1, showing a plan view of the underside of an example of a lid in accordance with the invention, complete with 8 such flaps (22), arranged in pairs between neighboring locking flange segments (36). It should be understood that more or fewer flaps (22) could be used to achieve proper holding of the gasket, without departing from the scope of this invention.

In the embodiments shown in the Figures, the added flaps hold the gasket in place until the lid is installed on the container for the first time. In the embodiment shown in FIGS. 2 to 7 and the embodiment of FIGS. 6 a and 7 a, once the rim (15) is removed from the peripheral channel (19) of the lid, the flaps (22) stay bent in their relief pockets, even when the lid is removed from the container. Although, the embodiments shown in FIGS. 7 and 7 a illustrate that the removal of the tear off strip is necessary to remove the lid from the container, it should be understood that the invention herein could be used with a lid not including a tear off strip.

A lid incorporating flaps and relief pockets in accordance with the herein invention has approximately the same volume and weight as a similar lid without such flaps. The design does not add or remove a considerable amount of material from a comparable lid rather it just molds it in a different shape. This aspect is relevant for cases where the volume or the weight of the lid is an important feature. Other than the added weight of the gasket, the new lid weighs approximately the same as a comparable lid without said flaps, molded therein. For example, the lid as shown in drawings would be similar in weight to the lid shown in International Patent Application PCT/CA00/01406 having a publication number WO/0140070, which is incorporated herein by reference.

Another aspect of this invention relates to the geometry of the tool used to inject the lid with flaps. As can be seen in FIG. 8, in the core ring, grooves forming the flaps extend towards the open end of the lid, creating positively angled flaps, illustrated as flap 22 p in FIG. 8. This orientation helps them release easily when the stripping element (stripper ring in FIG. 8) pushes the molded lid away from the core side, without requiring the use of expensive slides. It should be understood though that Flaps could be also be molded at a horizontal plane (22 h) or negative angle (22 n) because intermittent locking flange segments (36) expand over the core ring, allowing the flaps to demold regardless of their angle. FIG. 8 illustrates the different angles of flaps, superimposed upon one another. Upon release of the core ring, the intermittent locking flange segments (36) flex out together with the upper portion of the skirt (16), thereby facilitating flap demolding.

Although the Figures show a particular embodiment of a lid and container, it should be understood that the invention herein may be utilized with any lid for a container, the container forming an upper rim portion, the lid comprising a central portion and a peripheral skirt portion forming a downwardly disposed channel extending around the periphery of said lid, the channel adapted to overlie the container upper rim portion and to hold a sealing gasket therein at an upper portion of said channel at a position above said upper rim portion, said skirt portion forming a plurality of bendable flaps extending within said channel, each of which being movable from a first position wherein each said flap extends across a portion of said channel preventing said gasket from falling out of the channel to a second position wherein each said flap is positioned within a relief pocket formed within said skirt wall, urged there by the rim portion of the container as it is inserted into the channel. It should be further understood that the lid of the herein invention may be circular or rectangular or square or other suitable shape.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. 

1. A lid for a container, said container forming an upper rim portion, the lid comprising: a central portion and a peripheral skirt portion forming a downwardly disposed channel extending around the periphery of said lid, said channel adapted to overlie the container upper rim portion and to hold a sealing gasket therein at an upper portion of said channel at a position above said upper rim portion when said channel overlies said upper rim portion, said skirt portion forming a plurality of bendable flaps extending within said channel, each of which being movable from a first position wherein each said flap extends across a portion of said channel preventing said gasket from falling out of the channel to a second position wherein each said flap is positioned within a relief pocket formed within said skirt wall.
 2. A lid as recited in claim 1 wherein each said flap is urged from said first position to said second position by said rim as said rim is inserted within said channel and pressed into engagement with said gasket.
 3. A lid as recited in claim 1 wherein said flap extends from said skirt portion at a position below said pocket, and may be bent from said first position into said pocket by said rim portion as it is inserted within said channel.
 4. A lid as recited in claim 1 wherein said flap is inserted in a clearance fit within said pocket and remains in said pocket once urged therein by said rim portion.
 5. A lid as recited in claim 1 wherein said lid is formed of resilient material, with each said flap being resiliently biased in said first position.
 6. A lid as recited in claim 5 wherein each said flap is pressed into friction fit engagement within said pocket and is fixed within said pocket once pressed therein by said rim portion, as said rim is inserted within said channel.
 7. A lid as recited in claim 6 wherein an portion of the skirt forming an upper portion of the pocket, is downwardly tapered as it extends outwardly from within said pocket, said upper portion of the pocket engages in friction fit an upper portion of said flap within said pocket, thereby securing said flap within said pocket.
 8. A lid as recited in claim 1 wherein said flaps are positioned around the periphery of the lid at regularly spaced intervals.
 9. A lid as recited in claim 1 wherein the container further includes upper and lower peripheral, annular outwardly disposed locking flanges, said flanges having undersides for locking engagement with the container lid, the downwardly disposed channel of the lid further adapted to overlie the container locking flanges and the peripheral skirt portion further defining a peripheral groove dividing said skirt into a skirt upper portion located adjacent to the container upper locking flange, and a lower tear-off strip portion located adjacent to the container lower locking flange; the skirt upper portion having inwardly disposed intermittent locking flange segments adapted to engage the underside of the container upper locking flange; the skirt upper portion also being formed with thin membrane windows therein on either side of the locking flange segments and bordering on the peripheral groove; and the tear-off strip portion defining an inwardly disposed locking flange adapted to engage the underside of the container lower locking flange, so that removal of the tear-off strip portion leaves downwardly disposed thin membrane notches on either side of the locking flange segments, the flaps being formed on the upper skirt portion.
 10. A lid as recited in claim 9 wherein a pair of said flaps are positioned at regularly spaced intervals between adjacent locking flange segments.
 11. A lid as claimed in claim 1 wherein the thin membrane windows are formed with openings therethrough bordering on the annular groove, so that removal of the tear-off strip portion leaves downwardly disposed open notches on either side of the locking flange segments.
 12. A lid as claimed in claim 1 wherein the thin membrane are formed with strengthening ribs therein.
 13. A lid as claimed in claim 1 wherein the periphery of the lid and container is rectangular.
 14. A lid as claimed in claim 1 wherein the periphery of lid and container is circular.
 15. A lid as claimed in claim 1 wherein in said first position each said flap extends across said portion of said channel preventing said gasket from falling out of the channel, and leaves an open portion which allows the gasket to be inserted through into said channel if slightly compressed away from said flap. 